/****************************************************************************
 *
 * Copyright 2016 Samsung Electronics All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific
 * language governing permissions and limitations under the License.
 *
 ****************************************************************************/
/****************************************************************************
 * fs/vfs/fs_rename.c
 *
 *   Copyright (C) 2007-2009, 2014 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <gnutt@nuttx.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name NuttX nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <tinyara/config.h>

#include <stdio.h>
#include <errno.h>
#include <tinyara/fs/fs.h>

#include "inode/inode.h"

/****************************************************************************
 * Pre-processor Definitions
 ****************************************************************************/

#undef FS_HAVE_WRITABLE_MOUNTPOINT
#if !defined(CONFIG_DISABLE_MOUNTPOINT) && defined(CONFIG_FS_WRITABLE) && \
	CONFIG_NFILE_STREAMS > 0
#define FS_HAVE_WRITABLE_MOUNTPOINT 1
#endif

#undef FS_HAVE_PSEUDOFS_OPERATIONS
#if !defined(CONFIG_DISABLE_PSEUDOFS_OPERATIONS) && CONFIG_NFILE_STREAMS > 0
#define FS_HAVE_PSEUDOFS_OPERATIONS 1
#endif

#undef FS_HAVE_RENAME
#if defined(FS_HAVE_WRITABLE_MOUNTPOINT) || defined(FS_HAVE_PSEUDOFS_OPERATIONS)
#define FS_HAVE_RENAME 1
#endif

#ifdef FS_HAVE_RENAME

/****************************************************************************
 * Private Variables
 ****************************************************************************/

/****************************************************************************
 * Public Variables
 ****************************************************************************/

/****************************************************************************
 * Private Functions
 ****************************************************************************/

/****************************************************************************
 * Public Functions
 ****************************************************************************/

/****************************************************************************
 * Name: rename
 *
 * Description:  Remove a file managed a mountpoint
 *
 ****************************************************************************/

int rename(FAR const char *oldpath, FAR const char *newpath)
{
	FAR struct inode *oldinode;
	FAR struct inode *newinode;
	const char *oldrelpath = NULL;
#ifndef CONFIG_DISABLE_MOUNTPOINT
	const char *newrelpath = NULL;
#endif
	int errcode;
	int ret;

	/* Ignore paths that are interpreted as the root directory which has no name
	 * and cannot be moved
	 */

	if (!oldpath || *oldpath == '\0' || oldpath[0] != '/' || !newpath || *newpath == '\0' || newpath[0] != '/') {
		errcode = EINVAL;
		goto errout;
	}

	/* Get an inode that includes the oldpath */

	oldinode = inode_find(oldpath, &oldrelpath);
	if (!oldinode) {
		/* There is no inode that includes in this path */

		errcode = ENOENT;
		goto errout;
	}
#ifndef CONFIG_DISABLE_MOUNTPOINT
	/* Verify that the old inode is a valid mountpoint. */

	if (INODE_IS_MOUNTPT(oldinode) && oldinode->u.i_mops) {
		/* Get an inode for the new relpath -- it should like on the same
		 * mountpoint
		 */

		newinode = inode_find(newpath, &newrelpath);
		if (!newinode) {
			/* There is no mountpoint that includes in this path */

			errcode = ENOENT;
			goto errout_with_oldinode;
		}

		/* Verify that the two paths lie on the same mountpoint inode */

		if (oldinode != newinode) {
			errcode = EXDEV;
			goto errout_with_newinode;
		}

		/* Perform the rename operation using the relative paths
		 * at the common mountpoint.
		 */

		if (oldinode->u.i_mops->rename) {
			ret = oldinode->u.i_mops->rename(oldinode, oldrelpath, newrelpath);
			if (ret < 0) {
				errcode = -ret;
				goto errout_with_newinode;
			}
		} else {
			errcode = ENOSYS;
			goto errout_with_newinode;
		}

		/* Successfully renamed */

		inode_release(newinode);
	} else
#endif
#ifndef CONFIG_DISABLE_PSEUDOFS_OPERATIONS
	{
		/* Create a new, empty inode at the destination location */

		inode_semtake();
		ret = inode_reserve(newpath, &newinode);
		if (ret < 0) {
			/* It is an error if a node at newpath already exists in the tree
			 * OR if we fail to allocate memory for the new inode (and possibly
			 * any new intermediate path segments).
			 */

			inode_semgive();
			errcode = EEXIST;
			goto errout_with_oldinode;
		}

		/* Copy the inode state from the old inode to the newly allocated inode */

		newinode->i_child = oldinode->i_child;	/* Link to lower level inode */
		newinode->i_flags = oldinode->i_flags;	/* Flags for inode */
		newinode->u.i_ops = oldinode->u.i_ops;	/* Inode operations */
#ifdef CONFIG_FILE_MODE
		newinode->i_mode = oldinode->i_mode;	/* Access mode flags */
#endif
		newinode->i_private = oldinode->i_private;	/* Per inode driver private data */

		/* We now have two copies of the inode.  One with a reference count of
		 * zero (the new one), and one that may have multiple references
		 * including one by this logic (the old one)
		 *
		 * Remove the old inode.  Because we hold a reference count on the
		 * inode, it will not be deleted now.  It will be deleted when all of
		 * the references to to the inode have been released (perhaps when
		 * inode_release() is called below).  inode_remove() should return
		 * -EBUSY to indicate that the inode was not deleted now.
		 */

		ret = inode_remove(oldpath);
		if (ret < 0 && ret != -EBUSY) {
			/* Remove the new node we just recreated */

			(void)inode_remove(newpath);
			inode_semgive();

			errcode = -ret;
			goto errout_with_oldinode;
		}

		/* Remove all of the children from the unlinked inode */

		oldinode->i_child = NULL;
		inode_semgive();
	}
#else
	{
		errcode = ENXIO;
		goto errout;
	}
#endif

	/* Successfully renamed */

	inode_release(oldinode);
	return OK;

#ifndef CONFIG_DISABLE_MOUNTPOINT
errout_with_newinode:
	inode_release(newinode);
#endif
errout_with_oldinode:
	inode_release(oldinode);
errout:
	set_errno(errcode);
	return ERROR;
}

#endif							/* FS_HAVE_RENAME */
